In self-steering bogies, the radial adjustment of their wheelsets for curve negotiation is effected by the longitudinal forces that arise at contact surface points of the wheels as they travel around curves. Such radial adjustability is generally proposed to reduce friction and wear of the wheels and rails by minimizing lateral creep forces. The use of such self-steering bogies has been considered both for unpowered railroad cars and for locomotives with motorized axles. The present inventors have recognized a need for improvements in bogie design.